JavaScript is a programming language commonly used as part of webpages. It is also used in various applications such as PDF documents, site-specific browsers, and desktop widgets. The support for JavaScript is included in the host the program.

JavaScript is a different language and environment to Java. JavaScript copies many names and naming conventions from Java, but the two languages are otherwise unrelated and have very different semantics. The key design principles within JavaScript are taken from the Self and Scheme programming languages.